RFCs don't have to be about getting explicit approval or permission. Instead, they can be used as a tool to ask for feedback on a decision a team has made. It checks for major objections or reason not to proceed with the decision. Even then, you can still proceed with the decision - but remember you are accountable.
When using it in this way, bias the RFC towards action. If no-one comments, we're still going to do it. Teams are often autonomous, we can be responsible and accountable to make these decisions.
Creating a public timeline at the start aids this. It shows an intention for actions happening, and gives explicit next steps to readers. It follows the same line of thinking - if no-one is greatly against it, here's how we'll be moving forward.